JP2807248B2 - Deinking agent for recycled paper - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deinking agent used when reclaiming high-quality waste paper such as newspaper waste paper, magazine waste paper and the like, and high-quality waste paper such as colored waste paper.

[Prior art / problems] In recent years, the shortage of paper pulp, soaring costs of wood and chips, resource conservation policies, and the like have placed increasing emphasis on the recycling of waste paper.

However, deinking of used paper becomes more difficult than before due to the diversification of printing inks and printing methods, and the increase in the types of processed paper, as well as replacement of printing paper for newspapers and magazines or bleached craft pulp. Due to the expansion of recycled paper applications, there has been a demand for recycled paper having high whiteness, a bright color tone, and a small amount of residual ink.

Conventionally, the recycling of waste paper has required alkali metal hydroxides such as caustic soda, sodium carbonate and sodium silicate, inorganic chemicals such as carbonates and silicates, and bleaching such as hydrogen peroxide and hypochlorite. Agents, ethylenediaminetetraacetate, diethylenetriaminepentaacetate, and other sequestering agents, as well as nonionic interfaces such as polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene polyoxypropylene block polymers, and higher fatty acid alkanolamides An activator, and an alkylbenzene sulfonate, a higher alcohol sulfate,
Anionic surfactants such as higher alcohol ether sulfates and dialkyl sulfosuccinates have been used alone or in combination as deinking agents.

However, these conventional deinking agents have insufficient cohesive force of the desorbed ink, and only low-quality recycled paper can be obtained.
Attempts have been made to use mineral oil, higher fatty acids or their salts as deinking components in order to increase the cohesive force of the desorbed ink during the flotation process.However, mineral oil has a low flash point and a strong odor. There are many problems as described above, and the cohesive force of the ink is also insufficient, so that a sufficient effect cannot be exhibited unless it is added in a large amount.

In addition, higher fatty acids or salts thereof have strong ink cohesion, but have low foaming power, so that the ink that has coagulated and floated in the flotation process is not sufficiently removed and remains in the product, causing troubles such as ink spots. There were drawbacks that occurred.

Attempts have been made to use nonionic or anionic surfactants as foaming agents to compensate for this, but these foaming agents are components that essentially act as dispersants, and the strong carbon agglomeration of fatty acids There is a drawback that the removal of the ink becomes insufficient due to the effect of inhibiting the force.

Accordingly, an object of the present invention is to provide a deinking agent which has sufficient ink collecting ability and moderate foaming property in a flotation step, and which gives a low residual carbon and high whiteness recycled paper.

[Means for Solving the Problems] The present inventors have made intensive studies to solve the above-mentioned drawbacks, and as a result, completed the present invention.

That is, the deinking agent of the present invention contains 0.5 to 20 parts by weight of two or more alkylene oxides containing 10 to 95% by weight of ethylene oxide in alkylene oxide per 1 part by weight of castor oil and / or hydrogenated castor oil. It is characterized by containing castor oil and / or hydrogenated castor oil alkylene oxide adduct to which only random addition has been made.

In the deinking agent of the present invention, the alkylene oxide added to castor oil and / or hardened castor oil includes:
Examples include ethylene oxide, propylene oxide, and butylene oxide.

The addition amount of the alkylene oxide is 0.5 to 20 parts by weight, preferably 1 to 10 parts by weight, based on 1 part by weight of the castor oil and / or the hardened castor oil as a raw material. And foaming becomes unstable.

Further, the content of ethylene oxide in the alkylene oxide is required to be 10 to 95% by weight, preferably 25 to 80% by weight, and if it is outside this range, sufficient cohesiveness of the ink is not exhibited.

The addition of the alkylene oxide is performed by random addition. This is because the cohesion of the ink is inferior if only the block is added. For example, random addition of the alkylene oxide to castor oil and / or hydrogenated castor oil (preferably random addition of 1 to 10 moles of the alkylene oxide per hydroxyl group of castor oil and / or hydrogenated castor oil) followed by random addition of the alkylene oxide It is preferable in terms of cohesiveness to perform partial random addition by performing, for example, performing block addition only.

The addition of these alkylene oxides may be carried out as long as a compound or composition corresponding to, for example, castor oil and / or hydrogenated castor oil alkylene oxide adducts obtained only by random addition is obtained. If a compound or a composition corresponding to castor oil and / or hydrogenated castor oil alkylene oxide adduct obtained by only random addition by addition or other synthetic methods can be used in the present invention as well.

The deinking agent of the present invention may contain other known deinking agents, bleaching agents, sequestering agents, and the like as desired within the scope of the present invention. It can be used in combination with other deinking agents, bleaching agents, sequestering agents and the like.

The amount of the deinking agent of the present invention depends on the type of waste paper,
The castor oil and / or the hydrogenated castor oil alkylene oxide adduct may be added in an amount of about 0.05 to 1.0% by weight, preferably 0.1 to 0.6% by weight, based on the raw waste paper.

If the amount is less than the above amount, the deinking effect is insufficient. There is no particular upper limit on the amount of castor oil and / or hydrogenated castor oil alkylene oxide adduct. However, even if it is added in the above amount, deinking hardening will not be further improved, and the amount is preferably not more than the above amount in terms of industrial suitability. .

The deinking agent of the present invention may be added in the deinking step at, for example, a pulper and / or a retention tower.

When the waste paper is recycled using the deinking agent of the present invention, the ink is appropriately agglomerated in the flotation step, adheres to air bubbles and floats, thereby facilitating removal of the ink and other foreign substances, Recycled paper with high whiteness and little residual ink can be obtained.

[Examples] Hereinafter, the present invention will be further described with reference to Examples, but the present invention is not limited thereto.

Hunter whiteness is measured by a colorimeter (Nippon Denshoku)
The residual carbon was measured by an image analyzer (× 65: Pierce).

AO, EO, PO, and BO in the table represent alkylene oxide, ethylene oxide, propylene oxide, and butylene oxide, respectively.

Example 1 (Recycled waste paper treatment) 50 g of newspaper / magazine waste paper was cut into 2 cm squares, placed in a mixer, and water at 30 ° C. was added to adjust the waste paper concentration to 5% by weight.

0.3% by weight of various deinking agents shown in Table 1, 1.5% by weight of caustic soda, 3.5% by weight of sodium silicate No. 3,
The mixture was disintegrated by adding 1.0% by weight of hydrogen peroxide.

This was kept at 60 ° C. for 2 hours, and then diluted with water at a temperature of 30 ° C. and a waste paper concentration of 1% by weight, and subjected to a flotation treatment for 10 minutes using a flotator (manufactured by Far East Shinko) to remove the floss.

The treated pulp was hand-made with a tappy standard sheet machine (manufactured by Toyo Seiki), and the hunter whiteness and the residual carbon content were measured.

 The results are shown in Table 1.

Example 2 (High-quality waste paper treatment) 50 g of imitation and colored waste paper was cut into 2 cm squares, placed in a mixer, and water at 30 ° C. was added to adjust the waste paper concentration to 5% by weight.

0.3% by weight of various deinking agents shown in Table 2, 1.5% by weight of caustic soda, 3.5% by weight of sodium silicate No. 3,
The mixture was disintegrated by adding 1.2% by weight of hydrogen peroxide.

This was kept at 60 ° C. for 2 hours, and then the water was diluted with water to a temperature of 30 ° C. and a used paper concentration of 1% by weight, and a flotation treatment was performed for 10 minutes using a flotator (manufactured by Far East Shinko) to remove the floss.

The treated pulp was hand-made with a tappy standard sheet machine, and the hunter whiteness and the residual carbon content were measured.

 The results are shown in Table 2.

[Effect of the Invention] When used paper is recycled using the deinking agent of the present invention, the ink is appropriately agglomerated in the flotation process, adheres to bubbles, and floats, thereby removing ink and other foreign matter. , The whiteness is high, and recycled paper with little residual ink can be obtained.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) D21C 5/02

Claims (1)

(57) [Claims] 1. An alkylene oxide in which 0.5 to 20 parts by weight of two or more alkylene oxides containing 10 to 95% by weight of ethylene oxide are randomly added to 1 part by weight of castor oil and / or hydrogenated castor oil. A deinking agent for recycling used paper, comprising a castor oil and / or a hydrogenated castor oil alkylene oxide adduct.